TDM wireless communication systems are know to comprise a central controller that allocates a plurality of wireless communication resources, via base stations operably connected to the central controller, among a plurality of communication units. In such systems, the communication units (i.e., hand-held portable or in-car mobile radios) are assigned wireless communication resources in the form of a radio frequency (RF) carrier divided with respect to time into multiple timeslots. When transmitting a message, it is known in such systems to prefix information regarding the transmitting communication unit to the message. For instance, the push-to-talk identification (PTT ID) or alias name, as are known in the art, are often added to the beginning of a message. In this manner, the transmitting communication unit can provide information about itself, hereinafter referred to as caller data, to the receiving communication unit.
Two shortcomings currently exist with this method of transferring caller data. First, the receiving communication units has no ability to indicate if the caller data is even desired. That is, the receiving communication unit may not want to receive the caller data for every call it receives. This could be the case when two communication units are continuously transmitting and receiving with each other; there is no need to constantly identify the transmitting communication unit.
Second, even if the caller data is desired by the receiving communication unit, it has no control over what kind of caller data it receives. That is, the caller data sent by a transmitting communication unit (e.g., PTT IDs and/or alias names) is typically fixed; no other type of caller data can be sent. It would be useful to allow a user of a receiving communication unit to select the type of caller data received, such as current location, current heading, and current speed information of the transmitting communication unit. Therefore, a need exists for a method that overcomes the shortcomings of prior art methods of providing caller data, and allows caller data to be selectively provided on an as-needed basis.